Answer: 4.5 moles
Step-by-step explanation:
Given that:
volume of NaCl = 4.5 L
concentration of NaCl = 1M
(Note that 1M is the same as 1 mol/L
Amount of moles of NaCl = ?
Recall that the concentration of a solution depends on the amount of solute dissolved in a particular volume of solvent.
I.e Concentration in mol/L =
Amount in moles / Volume in liters
1 mol/L = Amount in moles / 4.5 L
Amount in moles = 1 mol/L x 4.5 L
= 4.5 moles
Thus, we need 4.5 moles of NaCl to dissolve in 4.5 L to make 1 M solution of NaCl.